| 153 |
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|
| 154 |
|
|
| 155 |
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\subsection{Uncertainty on the \ttll\ Background} |
| 156 |
< |
|
| 156 |
> |
\label{sec:ttdilbkgunc} |
| 157 |
|
The \ttbar\ background prediction is obtained from MC, with corrections |
| 158 |
|
derived from control samples in data. The uncertainty associated with |
| 159 |
|
the \ttbar\ background is derived from the level of closure of the |
| 177 |
|
\end{figure} |
| 178 |
|
|
| 179 |
|
|
| 180 |
< |
\subsubsection{Check of the uncertainty on the \ttll\ Acceptance} |
| 180 |
> |
\subsubsection{Check of the uncertainty on the \ttll\ Background} |
| 181 |
|
|
| 182 |
< |
The uncertainty associated with |
| 183 |
< |
the theoretical modeling of the \ttbar\ production and decay is |
| 184 |
< |
checked by comparing the background predictions obtained using |
| 182 |
> |
We check that the systematic uncertainty assigned to the \ttll\ background prediction |
| 183 |
> |
covers the uncertainty associated with |
| 184 |
> |
the theoretical modeling of the \ttbar\ production and decay |
| 185 |
> |
by comparing the background predictions obtained using |
| 186 |
|
alternative MC samples. It should be noted that the full analysis is |
| 187 |
|
performed with the alternative samples under consideration, |
| 188 |
|
including the derivation of the various data-to-MC scale factors. |
| 278 |
|
statistics. |
| 279 |
|
\item Within the limited statistics, there is no evidence that the |
| 280 |
|
situation changes as we go from signal region A to signal region E. |
| 281 |
< |
Therefore, we assess a systematic based on the relatively high |
| 282 |
< |
statistics |
| 283 |
< |
test in signal region A, and apply the same systematic uncertainty |
| 284 |
< |
to all other regions. |
| 281 |
> |
%Therefore, we assess a systematic based on the relatively high |
| 282 |
> |
%statistics |
| 283 |
> |
%test in signal region A, and apply the same systematic uncertainty |
| 284 |
> |
%to all other regions. |
| 285 |
> |
\item In signal regions B and above, the uncertainties assigned in Section~\ref{sec:ttdilbkgunc} |
| 286 |
> |
fully cover the alternative MC variations. |
| 287 |
|
\item In order to fully (as opposed as 1$\sigma$) cover the |
| 288 |
|
alternative MC variations in region A we would have to take a |
| 289 |
|
systematic |
| 290 |
< |
uncertainty of $\approx 10\%$. This would be driven by the |
| 290 |
> |
uncertainty of $\approx 10\%$ instead of $5\%$. This would be driven by the |
| 291 |
|
scale up/scale down variations, see Table~\ref{tab:fracdiff}. |
| 292 |
|
\end{itemize} |
| 293 |
|
|
| 384 |
|
up/scale |
| 385 |
|
down variations by a factor 2, we can see that a systematic |
| 386 |
|
uncertainty |
| 387 |
< |
of 6\% would fully cover all of the variations from different MC |
| 388 |
< |
samples in SRA and SRB. |
| 389 |
< |
The alternative MC models indicate that a 6\% systematic uncertainty to |
| 390 |
< |
cover the range of reasonable variations. |
| 391 |
< |
Note that this 6\% is also consistent with the level at which we are |
| 387 |
> |
of 5\% covers the range of reasonable variations from different MC |
| 388 |
> |
models in SRA and SRB. |
| 389 |
> |
%The alternative MC models indicate that a 6\% systematic uncertainty |
| 390 |
> |
%covers the range of reasonable variations. |
| 391 |
> |
Note that this 5\% is also consistent with the level at which we are |
| 392 |
|
able to test the closure of the method with alternative samples in CR5 for the high statistics |
| 393 |
|
regions (Table~\ref{tab:hugecr5yields}). |
| 394 |
|
The range of reasonable variations obtained with the alternative |
| 869 |
|
|
| 870 |
|
\clearpage |
| 871 |
|
\subsection{Summary of uncertainties} |
| 872 |
< |
\label{sec:bgunc-bottomline}. |
| 872 |
> |
\label{sec:bgunc-bottomline} |
| 873 |
> |
|
| 874 |
> |
The contribution to the total uncertainty from each source is given in Tables~\ref{tab:relativeuncertaintycomponents} and~\ref{tab:uncertaintycomponents} for the relative and absolute uncertainties, respectively. In the low-\met\ regions the dominant uncertainty comes from the top tail-to-peak ratio, $R_{top}$ (Section~\ref{sec:ttp}), while in the high-\met\ regions the \ttll\ systematic uncertainty dominates (Section~\ref{sec:ttdilbkgunc}). |
| 875 |
> |
|
| 876 |
|
\input{uncertainties_table.tex} |
| 877 |
|
|
| 878 |
+ |
|
| 879 |
+ |
|
| 880 |
+ |
|
| 881 |
+ |
|
| 882 |
|
%Figure.~\ref{fig:reliso} compares the relative track isolation |
| 883 |
|
%for events with a track with $\pt > 10~\GeV$ in addition to a selected |
| 884 |
|
%muon for $\Z+4$ jet events and various \ttll\ components. The |
